1. Field of the Invention
The present invention relates to three-dimensional display devices. More particularly, the invention relates to a three-dimensional display apparatus that can be used to display conventional pseudo three-dimensional images and true three-dimensional images using a CRT screen, an array of digital micromirror devices, an array of actuated micromirrors, or any other devices that can activate and deactivate multiple pixels simultaneously, at a high speed.
2. Description of the Prior Art
Three-dimensional displays are useful for many applications, including medical imaging, radar imaging, scientific visualizations, video games, and virtual reality computer programs. Many prior art devices have been proposed to display three-dimensional images; however, these prior art devices have proven to be either ineffective or too costly for the consumers of computer workstations.
For example, many prior art three-dimensional displays only create two-dimensional displays that merely simulate a three-dimensional display. Viewers wishing to see these three-dimensional displays must wear special glasses. Prior art three-dimensional displays that actually create three-dimensional images have been developed; however, these devices are typically too complicated and costly for most applications.
U.S. Pat. No. 6,005,608 (the ""608 patent) discloses a three-dimensional display apparatus that effectively generates and displays true three-dimensional images. Moreover, the ""608 patent apparatus is relatively inexpensive to manufacture and well suited for almost all applications requiring the display of three-dimensional images. However, the ""608 apparatus suffers from several limitations that limit its utility. For example, although the apparatus is effective at displaying three-dimensional images when all the information for the images is separately distributed over a large number of planes of views, it cannot effectively display three-dimensional images when most of the information for the images is distributed over just a few planes of view. This is because the ""608 patent apparatus uses a CRT display and a graphics driver to project three-dimensional images onto a moving screen, and all known graphics drivers are too slow to access all of the pixels of a CRT for a particular plane of view before the screen must be moved to a new plane of view. In addition, CRT""s electron beam deflection mechanism imposes limitations on the number of lines that can be drawn in one second.
Another limitation of the ""608 patent apparatus is that it can only display true three-dimensional images. This prevents the apparatus from being used with conventional three-dimensional graphics""software packages, which are designed to create only pseudo three-dimensional images on stationary screens.
The present invention solves the above-described problems and provides a distinct advance in the art of three-dimensional display devices. More particularly, the present invention provides a three-dimensional display apparatus that can effectively display three-dimensional images even when most of the information for the images is distributed over only a few planes of view. Alternatively, the apparatus of the present invention can display both conventional pseudo three-dimensional images and true three-dimensional images and can thus take advantage of conventional three-dimensional graphics software packages.
One embodiment of the apparatus of the present invention broadly includes: a screen; a screen moving assembly for moving the screen to a select number of different depth locations along a longitudinal axis defining a screen travel path; and an imaging assembly for displaying images on the screen as it is moved. The imaging assembly includes circuitry for receiving a 3D signal representative of a three-dimensional image and for separating the signal into a plurality of 2D signals each representative of a two-dimensional image within the three-dimensional image, and a plurality of image generators coupled with the circuitry by a plurality of channels for generating on the screen the two-dimensional images in a concurrent fashion as the screen is moved by the screen moving assembly.
In another embodiment of the present invention, the apparatus includes switching circuitry that permits a viewer to switch the apparatus between several display modes including a pseudo three-dimensional display mode and a true three-dimensional display mode. This permits the apparatus to be used with conventional three-dimensional graphics software packages.
These and other important aspects of the present invention are described more fully in the detailed description below.